// This file is part of Eigen, a lightweight C++ template library
// for linear algebra.
//
// Copyright (C) 2014 Benoit Steiner <benoit.steiner.goog@gmail.com>
//
// This Source Code Form is subject to the terms of the Mozilla
// Public License v. 2.0. If a copy of the MPL was not distributed
// with this file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include "main.h"

#include <Eigen/CXX11/Tensor>

template<typename Scalar>
static void
test_default()
{
	Tensor<Scalar, 1> vec(6);
	vec.setRandom();

	// Fixme: we should check that the generated numbers follow a uniform
	// distribution instead.
	for (int i = 1; i < 6; ++i) {
		VERIFY_IS_NOT_EQUAL(vec(i), vec(i - 1));
	}
}

template<typename Scalar>
static void
test_normal()
{
	Tensor<Scalar, 1> vec(6);
	vec.template setRandom<Eigen::internal::NormalRandomGenerator<Scalar>>();

	// Fixme: we should check that the generated numbers follow a gaussian
	// distribution instead.
	for (int i = 1; i < 6; ++i) {
		VERIFY_IS_NOT_EQUAL(vec(i), vec(i - 1));
	}
}

struct MyGenerator
{
	MyGenerator() {}
	MyGenerator(const MyGenerator&) {}

	// Return a random value to be used.  "element_location" is the
	// location of the entry to set in the tensor, it can typically
	// be ignored.
	int operator()(Eigen::DenseIndex element_location, Eigen::DenseIndex /*unused*/ = 0) const
	{
		return static_cast<int>(3 * element_location);
	}

	// Same as above but generates several numbers at a time.
	internal::packet_traits<int>::type packetOp(Eigen::DenseIndex packet_location,
												Eigen::DenseIndex /*unused*/ = 0) const
	{
		const int packetSize = internal::packet_traits<int>::size;
		EIGEN_ALIGN_MAX int values[packetSize];
		for (int i = 0; i < packetSize; ++i) {
			values[i] = static_cast<int>(3 * (packet_location + i));
		}
		return internal::pload<typename internal::packet_traits<int>::type>(values);
	}
};

static void
test_custom()
{
	Tensor<int, 1> vec(6);
	vec.setRandom<MyGenerator>();

	for (int i = 0; i < 6; ++i) {
		VERIFY_IS_EQUAL(vec(i), 3 * i);
	}
}

EIGEN_DECLARE_TEST(cxx11_tensor_random)
{
	CALL_SUBTEST((test_default<float>()));
	CALL_SUBTEST((test_normal<float>()));
	CALL_SUBTEST((test_default<double>()));
	CALL_SUBTEST((test_normal<double>()));
	CALL_SUBTEST((test_default<Eigen::half>()));
	CALL_SUBTEST((test_normal<Eigen::half>()));
	CALL_SUBTEST((test_default<Eigen::bfloat16>()));
	CALL_SUBTEST((test_normal<Eigen::bfloat16>()));
	CALL_SUBTEST(test_custom());
}
